(all the four co. are doing same type of businesswith different PAN and different namecan then separate registration?)Query is not correct. Single PAN is Single company. Different pan is different company. Can't four is separate Registere

Any person having multiple business verticals within a State or a Union territory, requiring a separate registration for any of its business verticals under sub-section (2) of section 25 shall be granted separate registration in respect of each of the verticals subject to the following conditions:
Such person has more than one business vertical as defined in clause (18) of section 2 ;
No business vertical of a taxable person shall be granted registration to pay tax under section 10 if any one of the other business verticals of the same person is paying tax under section 9.
Explanation.- Where any business vertical of a registered person that has been granted a separate registration becomes ineligible to pay tax under section 10, all other business verticals of the said person shall become ineligible to pay tax under the said section.
All separately registered business verticals of such person shall pay tax under the Act on supply of goods or services or both made to another registered business vertical of such person and issue a tax invoice for such supply.
A registered person eligible to obtain separate registration for business verticals may submit a separate application in FORM GST REG-01 in respect of each such vertical.
The provisions of rule 2 and rule 3 relating to verification and grant of registration shall, mutatis mutandis, apply to an application submitted under this rule.